This invention relates in general to structures for supporting a component on a closed channel structural member. In particular, this invention relates to an improved structure for a mounting bracket for supporting a steering gear or other ancillary device on a closed channel structural member, such as a hydroformed side rail in a vehicle frame assembly.
Many land vehicles in common use, such as automobiles, vans, and trucks, include a body and frame assembly that is supported upon a plurality of ground-engaging wheels by a resilient suspension system. The structures of known body and frame assemblies can be divided into two general categories, namely, separate and unitized. In a typical separate body and frame assembly, the structural components of the body portion and the frame portion of the vehicle are separate and independent from one another. When assembled, the frame portion of the assembly is resiliently supported upon the vehicle wheels by the suspension system and serves as a platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized use modern vehicles, such as large vans, sport utility vehicles, and trucks. In a typical unitized body and frame assembly, the structural components of the body portion and the frame portion are combined into an integral unit that is resiliently supported upon the vehicle wheels by the suspension system. Unitized body and frame assemblies of this general type are found in many relatively small modern vehicles, such as automobiles and minivans.
In many instances, it is necessary or desirable to secure one or more ancillary devices to portions of the vehicle body and frame assembly. For example, most vehicles are provided with a steering system including a steering wheel that is connected through a shaft to a steering gear mechanism that, in turn, is connected through one or more rods to the steered wheels of the vehicle. In such a steering system, it is common for the steering gear to be supported on some portion of the body and frame assembly of the vehicle. Similarly, a variety of other ancillary devices are also commonly supported on some portion of the body and frame assembly of the vehicle. Regardless of its specific nature, the ancillary device can be mounted on the vehicle body and frame assembly by initially securing a mounting bracket to the portion of the body and frame assembly of the vehicle, and subsequently securing the ancillary device to the bracket.
Traditionally, the various components of known vehicle body and frame assemblies have been formed from open channel structural members, i.e., structural members that have a non-continuous cross sectional shape (U-shaped or C-shaped channel members, for example). Such open channel structural members are usually formed from flat metal stock that is bent or otherwise deformed into the desired cross sectional shape. The non-continuous cross sectional shape of such open channel structural members allows mounting brackets to be secured thereto in a relatively easy manner to as to support ancillary devices thereon in the manner described above. For example, it is well known to form one or more apertures through mating portions of the mounting bracket and the open channel structural member. The apertures are aligned with one another, and threaded fasteners are inserted therethrough to secure the two pieces together. Nuts or other retaining members can be threaded onto the ends of the threaded fasteners and tightened to secure the mounting bracket to the open channel structural member. Because of the non-continuous cross sectional shape of the open channel structural member, the ends of the threaded fasteners are easily accessible. Furthermore, because the mating portions of the mounting bracket and the closed channel structural member are generally flat, the nuts on the ends of the threaded fasteners can be tightened as desired without causing damage to either the mounting bracket or the open channel structural member.
However, more recently, it has been proposed to form one or more of the various vehicle body and frame components from closed channel structural members, i.e., structural members that have a continuous cross sectional shape (tubular or box-shaped channel members, for example). This cross sectional shape is advantageous because it provides strength and rigidity to the vehicle body and frame component. Also, this cross sectional shape is desirable because it facilitates the use of hydroforming. Hydroforming is a well known process that uses pressurized fluid to deform a hollow member into a desired shape. The hollow member is initially disposed between two movable die sections of a hydroforming apparatus that, when closed together, define a die cavity having a desired final shape for the hollow member. Thereafter, the hollow member is filled with a pressurized fluid, typically a relatively incompressible liquid such as water. The pressure of the fluid is increased to a magnitude where the hollow member is expanded outwardly into conformance with the die cavity. As a result, the hollow member is deformed into the desired final shape for the workpiece.
Unfortunately, it has been found to be somewhat more difficult to secure the above-described mounting brackets and ancillary devices to such closed channel structural members. This is because access to the end of the threaded fastener located within the interior of the closed channel structural member is relatively difficult, thus making it relatively difficult to thread the nut or other retaining device thereon. To address this, it has been proposed to form aligned apertures through a pair of opposed walls of a closed channel structural member and to have the threaded fastener extend through such aligned apertures. Because the end of the threaded fastener extends completely through the closed channel structural member, it is easily accessible to thread the nut or other retaining device thereon. However, care must be taken to prevent the nut from being excessively tightened, which could cause collapsing deformation or other damage to the closed channel structural member. To prevent this from occurring, it has further been proposed to provide a hollow cylindrical spacer about the portion of the threaded fastener that is disposed within the closed channel structural member. Because access to the interior of the closed channel structure member is limited, as mentioned above, the use of such spacers is also relatively difficult. Thus, it would be desirable to provide an improved structure for a mounting bracket for securing an ancillary device to a closed channel structural member that is relatively simple and inexpensive in construction and operation.
This invention relates to an improved structure for a mounting bracket for securing a steering gear or other ancillary device to a closed channel structural member, such as a hydroformed side rail in a vehicle frame assembly. The side rail has a relatively large opening formed through one of the walls thereof. A mounting bracket is provided for supporting the ancillary, device on the side rail. The mounting bracket includes a generally flat web having upper and lower flanges extending therefrom. Between the two flanges, a reinforcing structure is provided. The reinforcing structure can include one or more spacers that extend laterally from the web. Each of the spacers may have a generally cylindrical bore formed therethrough. When assembled to the side rail, the upper and lower flanges of the mounting bracket respectively abut upper and lower walls of the side rail. At the same time, the reinforcing structure of the mounting bracket is received within the opening of the side rail, allowing the spacers to extend through the interior of the side rail into engagement with the inner surface of a wall thereof. The mounting bracket can then be secured to the side rail in a conventional manner, such as by welding. Torsional loads and other forces that are generated by operation of the ancillary device are transferred through the mounting bracket to the side rail. The strength of the side rail is increased by the engagement of the web and the flanges of the mounting bracket with the outer surfaces of the walls thereof. Additionally, the engagement of the reinforcing structure of the mounting bracket with the inner surface of the wall of the side rail provides additional strength. Thus, the mounting bracket facilitates the use of such ancillary devices on the side rail.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.